P-911: Ectopic pregnancy in women with no major risk factors

Abstract

Classically, risk factors for ectopic pregnancy (EP) are elicited from women who present with a symptomatic first trimester pregnancy, presumably to stratify risk. The purpose of this study was to address two unknown outcomes of this practice: (1) Do women with risk factors (RF) have a different clinical course from those who do not? (2) Does risk stratification alter the time until definitive diagnosis? Prospective cohort study of women with first trimester bleeding in a tertiary care hospital ultimately diagnosed with an EP. 367 women diagnosed with an EP were stratified by presence or absence of RF and compared in terms of time until diagnosis and clinical course. RF evaluated included history of pelvic inflammatory disease (PID), outpatient treatment of gonorrhea/Chlamydia (GC), intrauterine device (IUD), EP, abdominal/pelvic surgery and cesarean section (CS). Clinical presentation factors evaluated included pain and/or bleeding. Rate of rupture and time to diagnosis were compared (p ≤ 0.05 is statistically significant). A total 158 women (43%) did not have any of the major RF. Of these, 102 women (65%) were nulliparous. 110 (30%) of women had only one RF: past history of GC - 30 women (8%), PID - 30 women (8%), pelvic surgery - 22 women (6%), EP - 20 women (5%), IUD - 11 women (3%), and CS - 3 women (0.1%). A total of 62 women (17%) had two RF, and 37 women (10%) had three RF. None of the women had all the history RF. Overall, women with no RF tended to be younger than women with RF (26.8 years vs. 28 years respectively). Overall, presence of historical RF did not influence the rate of rupture. Rate of rupture in women with 0 RF = 13%, 1 RF = 14.5%, 2 RF = 16%, 3 RF = 13.5%. (p value 0.96). Women with no historical RF vs. those with RF (0, 1, 2 or 3) were more likely to have a delayed diagnosis (p = 0.04). Women who had 1 or more risk factors were more likely than those with no RF to have a minimum diagnosis delay of 2 days. Further comparison of the data yielded statistically significant results for 0 RF vs. 2 RF (p value 0.001), and 1 RF vs. 2 RF (p value 0.002). Clinical factors present included: bleeding only in 23 women (7%), pain only in 74 women (22%). Both pain and bleeding were seen in 171 women (51%), and 23 women (6%) presented with clinical symptoms other than pain or bleeding. Pain (with or without bleeding) was significantly associated with rupture (p = 0.002) and delayed diagnosis (p = 0.01). This association remained statistically significant for rupture (p = 0.0001), and for delayed diagnosis (p = 0.0007) even in the subgroup with pain only (no bleeding). Bleeding (with or without pain compared to no bleeding) was not associated with rupture or delayed diagnosis. While risk factors are commonly solicited in the hospital intake of a woman at risk for EP, the presence and number of RF are not related to risk of rupture. Counter intuitively, a greater number of RF noted in a woman’s history is associated with a longer time until diagnosis. Clinical factors such as pain and bleeding are a common part of presentation, but they do not always present concomitantly. Pain has a strong association with risk of rupture of an EP. In conclusion, collection of risk factors has a limited affect on current clinical care. Further risk stratification may aid in identifying women at risk for EP, and may help in identifying subsets of women at highest risk for rupture and morbidity.